Improvement in burglar-alarms



I. H ERZBERG & A. HERZBERG. Improvement in Burglar Alarms.

Patented AprH 2', I872.

UNITED STATES n'rnnr 4i;

IMPROVEMENT m BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 125,293, dated April'2, 1872.

Specification describing an Improvement in Burglar-Alarms, invented by ISAAC HERZ- nnner'and ABRAM Hnnznnne, both of the city and county of Philadelphia and State of Pennsylvania.

Improvement in Burglar-Alarms.

Our invention consists, first, of a doubleacting spring sliding bar in combination with a single wire and clock-work alarm mechanism, as fully described hereafter, whereby the cutting or pulling of the wire causes an alarm to be sounded; and, secondly, in the combination with the said sliding bar of a spring-click or equivalent device for retaining the bar in either of its two extreme positions.

In the accompanying drawing, Figure 1 is an exterior elevation of a burglar-alarm with our improvement; Figs. 2 and 3, enlarged views of portions of the same; Fig. 4, a view of the alarm mechanism.

To a board or suitable frame, A, is secured a train of clock-work, B, and a bell, D, the latter being struck by a hammer, E, which receives its motion from the clock-work, as plainly shown in Fig. 4, or in any other wellknown and suitable manner. spindles F of the train ot'clock-work is a wheel, Gr, having four or other suitable num-' berof teeth, a, and extending transversely across or over this wheel, and arranged to slide in openings formed for its reception. In the side plates 0 of the clock-work is a bar, H, furnished with an arm, d, the latter extending between the teeth of the wheel G and preventing all movement of the latter, and, consequently, of the clock-work and alarm, when the bar H is in the position shown in Figs. 1, 2, and 3, but, being removed from contact with and permitting the free movementof the said wheel, when the bar is caused to slide transversely across the latter in either direction. The said bar with its arm cl forms, in other words, a device for retaining and preventing the movement of the clock-work, and also for releasing the latter,'when necessary, by a simple sliding movement in either direction. The bar is attached at one end to a spring, I, which tends to draw its arm d away from the wheel G in the direction of the arrow 1, and at its opposite end to the operating On one of the wire or cord :12, by pulling upon which the said bar can be drawn in the opposite direction in f, and is thence conducted to those parts of the building where it would be most likely to be struck by or to attract the attention of a burglar. The tension of this wire upon the bar H is so regulated that it shall, in opposition to the power of the spring I, draw the said bar to the position shown in Fig. 2, and there retain it; or, in other words, to such a position that the arm (1 of the said bar shall extend between the teeth of and prevent all movement of the wheel Gr.- In the present instance we have combined an additional spring, y,witl1 the wire, for the purpose of regulating the tension of the latter; but this is not absolutely cssentialand may be. dispensed with. 1n fact, the spring I itself is not essential, as a cord or weight, or spring of a different character, could be substituted for the same.

The operation of the device, when set in the manner just described, will be readily understood. The slightest movement of the wire, whether caused by striking against the same or by cutting it,-will cause a corresponding movement of the bar in one direction or the other, and the consequent releasing of the clock-work and sounding of the alarm. If the' movement is caused by striking against and, consequently, pulling the wire, the bar will be drawn away from the wheel G in the direction of the arrow 2; but it the wire is cut and thus released a movement of the bar in the contrary direction, as indicated by the arrow 1, will be caused by the reaction of the spring I or its equivalent. In order to retain the bar. in either of its two extreme positions, and thus prevent it, when operated, from returning and stopping the movement of the wheel G and,

consequently, of the alarm, we have combined with the said bar and spring I a spring-click, J, adapted to a recess in the edge of one of the plates 1) of the clock-work, and having two notches, 'i and 41, adapted to the edge of the said recess, in the manner plainly shown in Fig. 2, so that the bar maybe retained by the said click when its arm is drawn away from the wheel in either direction.

rrron.

For the purpose of regulating the tension of the wire 00 we have found it convenient to use a double cord or piece of catgut, 2, which can be twisted or untwisted, so as to shorten or lengthen the wire, and thus enable the bar H to be properly adjusted and set.

We claim as our invention- 1. The double-acting spring sliding bar in combination with a single wire and clock-work mechanism.

2. The combination, with the said sliding bar of a spring-click or equivalent device for retaining the bar in either of its two extreme positions.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

ISA'AG' HERZBERG;

ABRAM HERZBERG.

Witnesses:

WM. A. STEEL, JOHN K. RUPERTUS. 

